How is potential to emit calculated?

Potential emissions are calculated by taking the maximum emission rate (lb/hr) times 8760 (hours/year) times the number of identical points and dividing by 2000 (lb/ton). For example, an emission unit that is capable of emitting 10 lb/hr (after control) of VOM would have potential emissions of 43.8 tons/year (10 x 8760 x 1 / 2000). Emission units that have a Federally Enforceable Permit Special Condition have their potential emissions calculated by taking the allowable emission rate (lb/hr) times the allowable amount of hours of operation times the number of identical sources and dividing by 2000 (lb/ton). For example, an emission unit that is capable of emitting 10 lbs/hr of VOM, but has a Permit Special Condition limiting VOM emissions to 2.5 lb/hr and 4000 hours of operation per year would have potential emissions of 5.0 tons/year (2.5 x 4000 x 1 / 2000). The potential emissions for the source are calculated by summing the potential emissions of all emission units. As time goes on, ...  more